This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-326044, filed Nov. 16, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a liquid crystal display device and, in particular, to an active matrix type liquid crystal display device having coloring layers on an array substrate side.
A liquid crystal display device includes two substrates having their alignment films arranged opposite to each other with a liquid crystal layer sandwiched between these two substrates. The two substrates are joined by a sealing material and hermetic sealing material to each other at their peripheral areas. Between the two substrates, granular spacers or columnar spacers are arranged to maintain the gap between the substrates to a predetermined value, the columnar spacer being formed from a resin by a photolithography method. In the case where a color display is made by the liquid crystal display device, red (R), green (G) and blue (B) coloring layers are generally arranged on one of these substrates.
Usually, a frame pattern having a light blocking property is formed on the outer side of the substrates display area to prevent a light leakage from backlight. As a frame pattern material use is made of a metal thin film, such as Cr, Mo, or W or a resin.
In the case where coloring layers are formed on the array substrate, in addition to the R, G, B coloring layers, a black coloring layer is used to form the columnar spacer and frame pattern simultaneously. At this time, the black coloring layer can be formed on the R, G, B coloring layers so as to provide a desired cell gap. In order to maintain the cell gap uniformly, the columnar spacers are provided also at the sealing section. In the case where, however, the frame pattern is so formed as to extend to the sealing section and made thicker, a distance between the columnar spacers and frame pattern is narrowed. This causes a process defect such as the contacting of the columnar spacers with the frame pattern and a resultant irregular gap formation. In order to prevent this, it is necessary to space the columnar spacers away from the frame pattern, so that the frame of the liquid crystal display device becomes wider.
In order to narrow the width of the frame of the liquid crystal device it is considered that the width of the frame pattern is made narrower. However, the extent to which the frame pattern and a bezel are overlapped becomes also narrower, thus resulting in a xe2x80x9clight leakagexe2x80x9d problem.
The present invention has been contrived in consideration of the above-mentioned problems and its object is to provide an active matrix type liquid crystal display device which can narrow a frame without a light leakage occurring.
In order to achieve the above-mentioned object of the present invention there is provided a liquid crystal display device comprising an array substrate including a display area having a plurality of scanning lines formed on an insulating substrate, a plurality of signal lines arranged in an intersecting relation to the scanning lines, switching elements arranged near each intersection between the scanning line and the signal line, coloring layers covering the scanning lines, signal lines and switching elements, and a plurality of pixel electrodes formed on the coloring layers and connected to the switching elements, a wiring line arranged along the outer peripheral portion of the display area and having a light blocking property, a plurality of spacers provided on the coloring layers in the display area, and a frame pattern formed around the display area to prevent a light leakage at the peripheral edge of the display area; an opposite substrate arranged opposite to the array substrate and spaced a predetermined gap from the array substrate by the spacers; a sealing material provided around the frame pattern and joining the peripheral edge portions of the array substrate and opposite substrate; and a liquid crystal layer sealed in the gap between the array substrate and the opposite substrate, wherein the wiring line has its portion arranged in an overlapping relation to the frame pattern to provide a light blocking area for blocking light at the outer peripheral portion of the frame pattern.
According to the liquid crystal display device of the present invention, the spacers include columnar spacers arranged on the outer side of the frame pattern and spaced from the frame pattern with a gap left and the wiring line is provided in an overlapping relation to the gap between the frame pattern and the columnar spacers provided on the outer side of the frame pattern.
According to the liquid crystal display device thus constructed, the wiring line having a light blocking property is arranged at the outer peripheral portion of the frame pattern to block light at the gap at the outer side portion of the frame pattern, that is, at the gap between the outermost peripheral side columnar spacers and the frame pattern. Even if, therefore, the frame pattern has its width narrowed to be spaced from the outermost peripheral side columnar spacers, the effective light blocking width of the frame area is made thicker and it is possible to provide a liquid crystal display device which can narrow the frame without a light leakage occurring.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.